Comments to Role of upper airway ultrasound in airway management

Abstract Tracheal ultrasound can be an alternative diagnostic tool in airway management, besides traditional confirmatory methods such as capnography and auscultation. The standard image is a hyperechoic air\u2013mucosa (A\u2013M) interface with a reverberation artifact posteriorly (comet-tail artifact). If the second A\u2013M interface appears, which we call a \u201cdouble-tract sign,\u201d esophageal intubation is considered